How does this skill handle bug fixes?

It requires writing a failing test that reproduces the reported bug before any code is modified, ensuring the fix is verified and prevents future regressions.

Are there any exceptions to the TDD rule?

Exceptions include throwaway prototypes, generated code, and configuration files, though it is recommended to consult with a human partner before skipping the workflow.

What does 'Verify Red' mean in this context?

Verify Red is a mandatory step where the AI runs the newly written test to confirm it fails for the expected reason, proving the test is actually checking the missing functionality.

What is the primary rule of this TDD skill?

The 'Iron Law' is that no production code can be written without a failing test first; if code is written beforehand, it must be deleted and restarted to ensure the test truly validates the behavior.

Why is writing tests after the code discouraged?

Tests written after code are often biased by the implementation, proving only what the code does rather than what it should do, which can miss critical edge cases.

Test-Driven Development (TDD)

Name: Test-Driven Development (TDD)
Author: EricGrill

byEricGrill

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セキュリティとテスト

Enforces a strict Red-Green-Refactor workflow to ensure high-quality, bug-free production code through test-first development.

This Claude Code skill implements a rigorous Test-Driven Development (TDD) framework, requiring that a failing test be written and verified before any implementation code is allowed. It guides the AI through the complete TDD cycle—Red, Green, and Refactor—ensuring that every new feature or bug fix is backed by automated tests. By prohibiting production code that wasn't preceded by a failing test, this skill eliminates technical debt, prevents regressions, and promotes clean, minimalist software architecture that is easy to maintain.

主な機能

01Mandatory verification of failing tests before implementation

022 GitHub stars

03Minimalist code generation focused on passing specific tests

04Anti-pattern detection and automated restart protocols

05Strict Red-Green-Refactor cycle enforcement

06Continuous refactoring guidance to maintain code health

ユースケース

01Safely refactoring legacy codebases by establishing a test-driven safety net.

02Resolving complex bugs by first reproducing them with a failing test case.

03Developing new software features with 100% test coverage and high confidence.

What are Skills?·How to Install

Install with 🐟 Skill.Fish

npx skillfish add ericgrill/agents-skills-plugins test-driven-development

For use in Claude.ai and ChatGPT

Download Skill